<template>
    <p>age: {{ person.age }}, name: {{ person.name }}</p>
</template>

<script>
import { reactive } from 'vue'

export default {
  name: 'reactive',
  setup () {
    const person = reactive({
      age: 20,
      name: 'leyo'
    })

    setTimeout(() => {
      person.age = 25
    }, 1500)

    return {
      person
    }
  }
}
// 结果
// age: 20, name: leyo
// age: 25, name: leyo
</script>
